ES2346568T3 - HERMETIC COMPRESSOR WITH INTERNAL THERMAL INSULATION. - Google Patents

Abstract

A hermetic compressor with internal thermal insulation, comprising: a compression cylinder having one end closed by a valve plate provided with a discharge orifice and having a front face against which is mounted a cylinder cover internally defining a discharge chamber; and a spacing duct having one inlet end hermetically mounted to the front face of the valve plate and open to the discharge orifice and an outlet end hermetically mounted to the cylinder cover and open to the interior of the discharge chamber, said spacing duct defining a hermetic fluid communication between the interior of the compression cylinder and the discharge chamber maintaining the cylinder cover spaced from the valve plate and defining, with the latter, an annular plenum around said spacing duct.

Description

Hermetic compressor with thermal insulation internal.

Field of the Invention

The present invention relates to a compressor airtight of the type used in refrigeration appliances, such as refrigerators and freezers, and that allows isolation thermal hot regions inside the compressor, which are heated by the heat generated, with gas compression during the operation of the compressor and, more particularly, of the region of the cylinder cover, in which the gas is discharged.

Background of the invention

Refrigeration compressors have been subject of studies that aim to improve the performance of these compressors Among the various points of this performance that should be improved, you can indicate the increase in the amount of gas refrigerant removed during aspiration and reduction of power required to compress the refrigerant gas. With the final purpose to achieve such objectives, it is necessary to reduce the temperature of the refrigerant gas in the suction (increasing its mass specific) and also reduce the wall temperature of the compression chamber that contacts the refrigerant gas. He development of solutions that favor the reduction of levels of temperature of the compressor and of the flows dissipated by the hot parts of it is one of the feasible ways of achieve these goals

Hermetic compressors of the type used in refrigeration systems usually comprise, inside of a housing, a motor-compressor assembly that it has a cylinder block, in which a cylinder is defined that has an end closed by a cylinder head and that defines internally a discharge chamber in fluid communication selective with a defined compression chamber inside the cylinder and closed by a valve plate provided between the closed end of the cylinder and the cylinder head, said communication of fluid through suction and discharge holes provided on the valve plate and they close selectively and respectively by suction and discharge valves, which are usually carried by the valve plate.

One of the main causes responsible for heating of the internal components of the compressor is its discharge system, which includes the entire gas path refrigerant, from its escape from the compression chamber to the discharge of said refrigerant gas from inside the compressor. This is because the refrigerant gas reaches the maximum temperature levels during compression within the engine-compressor and heat cylinder generated by such compression is dissipated for others compressor components, during gas path refrigerant from the compression chamber inside the cylinder to discharge from inside the compressor housing.

A solution to avoid this dissipation of energy consists in isolating the gas discharge system from the rest Compressor By doing this, the extremely hot gas escaped from the compression chamber will pass through the system discharge without transferring heat to the other components, reducing in this way the temperature levels of the compressor in general.

Solutions to isolate the discharge system are you can find the patent US3926009, in which the tube of gas discharge is defined with a double wall, to reduce the minimum heat transfer the gas under compression to the inside the housing, and in US4371319, in which each one of the parts of the cylinder cover, the silencer of discharge and the discharge tube are surrounded by an element of thermal insulation with the same purpose of minimizing the gas heat transfer under compression to the inside of the housing described in US3936009.

In the vast majority of compressors hermetic refrigeration, mainly of the type of movement alternatively, the compressor discharge system comprises a first discharge chamber defined inside the cylinder cover, and located after the valve plate and receiving the gas that proceeds from the compression cylinder. This gas passes subsequently through other cameras before reaching a tube compressor discharge, which conducts the refrigerant gas compressed from the compressor housing to a system cooling, to which said compressor is normally associated.

Studies have proven that one of the causes mainly responsible for heating the cylinder compression is the heat flow generated by the gas in the lid of the cylinder, which heats the valve plate and, by conduction, heats the top of the cylinder block, in the region of The compression chamber of the compression cylinder.

The reduction of this heat flow has a positive impact on reducing the temperature of the cylinder and, consequently, in the reduction of compression power.

The known prior art presents different alternatives to make a transfer reduction possible of heat from the region of the cylinder cover to regions inside the shell distant from it. Devices are known, such as heat exchangers, for example machines "Stirling", as taught in US6347523; the provision of fins on the cylinder heads and the use of a system auxiliary air movement; the use of heat pipes; the use of fluid pumping systems using pumps powered by oscillating mechanical or electrical movement, among others. But nevertheless, said known solutions do not minimize transfer of heat between the cylinder cover and the cylinder block, due to to the discharge of gas from the compression chamber to the chamber Download

US 5096 395 A1 describes a valve discharge for an hermetic reciprocating compressor, comprising a cylinder cover that is mounted so conventional directly on the valve plate. Valve known download includes a rear bumper member that is configured as an oblong body, which is planned within the download camera and is provided internally with a camera longitudinal which is open at one end towards a hole of discharge on the valve plate and at the opposite end of the Inside the discharge chamber. Inside the stop member rear is housed a coil spring with one end fixed on one end of the backgauge member and with the other end leaning against the outer face of a sealing disc that covers a discharge hole. The rear bumper member acts as a rear stop and as a side guide for the spring and at the same time acts as a backstop that limits a real maximum displacement of the sealing disc while the valve seat is open. The rear bumper member incorporates radial tabs that are partially mounted in a recess located in the face outside of the valve plate. The radial tabs are fixed to the valve plate by means of rivets that are placed at through holes in the tabs of the rear bumper member and in the valve plate, respectively. However, the fixation direct from the cylinder cover to the valve plate and even the contact between the hot gas in the discharge chamber with portions of the upper side of the valve plate gives as result some heat flow from the hot gas in the chamber of discharge and from the cover to the valve plate.

US 2 382 716 A1 describes a gas compressor with a compression cylinder, which has a end closed by a valve structure consisting of two members, one of which constitutes a valve seat or valve holder, while the other serves as a housing of valve and means for limiting the movement of the valve. Both of them members are forcibly held against the cylinder by a threaded valve retaining member, which has a plurality of inclined steps arranged in the periphery and a hole central. The plurality of the inclined steps arranged in the periphery as well as the central hole are each of them open to the discharge chamber formed between the cylinder cover and the blocking member. In this arrangement, hot gases in the download chamber are always in contact with all the surface of the locking member and of the valve plate that of again allows the passage of heat flow from hot gases in the inside of the discharge chamber to the valve plate.

In the discharge valve arrangement of compressor as described by US 4 352 377 A1, the Compression chamber is closed by a valve plate. In the which are provided a suction hole and a hole of discharge with corresponding valve means to open them and close them In addition, in this known arrangement, the cover of cylinder is sealed and fixed to the valve plate, with a discharge chamber defined inside the cylinder cover, which filled with the cooling gas admitted through the orifice of discharge. Again, the hot gas and the discharge chamber of this previous solution come into direct contact with the plate valve, even in an area of a portion of the valve plate around the discharge hole, which allows the flow of heat from the hot gas inside the discharge chamber to the valve plate

In addition, the hermetic compressor according to the Figure 9 of US 5,816,783 (closest prior art) A1 shows a cylinder cover that is mounted above conventional way and fixed to the valve plates. This way, the passage of heat flow from the hot gas inside the discharge chamber and heat flow from the cylinder cover hot until the valve plate takes place in functioning.

Objectives of the invention

Therefore, an object of the present invention is to provide a hermetic compressor with thermal insulation internal, particularly in the cylinder block, which increases compression efficiency, increasing the ability to gas suction of the compressor and reducing the power required to compress said gas.

In addition, an object of the present invention is provide a compressor, as mentioned above, that reduce the temperature in the adjacent cylinder block region to the region of the cylinder cover mounted above.

Another object of the present invention is provide a hermetic compressor, as mentioned Previously, it has a reduced thermal profile.

Summary of the Invention

These and other objectives are achieved through a hermetic compressor with internal thermal insulation that comprises: a housing that internally carries a block of cylinders, in which a compression cylinder is defined, which It has one end closed by a valve plate provided with a discharge hole and a suction hole, said having valve plate a front face against which a cylinder cover defining a discharge chamber, comprising, further, said hermetic compressor a spacing conduit that has an inlet end mounted tightly on the face front of the valve plate and open towards the orifice of discharge of the valve plate, outside its orifice suction, and an outlet end hermetically mounted on the lid of the cylinder and open into the discharge chamber, presenting the inlet end of the spacing conduit a cross sectional area at least equal to that of the hole of discharge, said said spacing conduit a communication of airtight fluid between the inside of the compression cylinder and the discharge chamber through the discharge hole, said spacing conduit keeping the cylinder cover spaced from the valve plate and defining, with the latter, an annular chamber around said spacing conduit, preventing the flow of heat from the hot gas inside from the discharge chamber to the valve plate.

The present invention, as described Previously, it provides insulation for heat flow between the gas in the cylinder cover and the compression block. This isolation is done by the provision of an interstitium between the valve plate and cylinder cover, generating a volume of gas that reduces heat transfer from the gas hot discharge to the valve plate and therefore by conduction, to the top of the compression cylinder of the compressor.

Brief description of the drawings

The invention will now be described with reference to the attached drawings, given by way of example of the possible embodiments of the invention, and in which:

Figure 1 represents a partial view schematic of the cross section of an airtight buyer who illustrates the region of the cylinder cover shaped according to the prior art

Figure 2 represents a partial view schematic of the cross section of the cylinder block illustrated in figure 1, indicating, by means of continuous arrows, the trajectory of a refrigerant gas under compression which is discharged into the cylinder cover and, by means of arrows of strokes, part of the direction of heat propagation from the discharge chamber to the cylinder cover.

Figure 3 represents in a schematic view similar to that of figure 2, a first construction option for The internal thermal insulation system of the compressor, according with the present invention.

Figure 4 shows an embodiment of the present invention, as illustrated in Figure 3 and in which the spacing conduit is supported by the plate valves

Figure 5 is a perspective view of a cylinder cover mounted on a valve plate formed according with the present invention and as illustrated in figure 4.

Figure 6 is a perspective view of a cylinder cover construction that has its front face configured to be mounted on a valve plate of the type illustrated in figure 4.

Figure 7 represents, in a schematic view similar to that of figure 3, a second construction option for The internal thermal insulation system of the compressor, according with the present invention.

Figures 8 and 8a are respectively views in perspective of a cylinder cover and a conduit of spacing, formed according to the second mode of embodiment of the present invention, as illustrated in a manner schematic in figure 7 and in which the spacing conduit It is supported by the cylinder cover.

Figures 9 and 9a present, respectively, and in a perspective view, a valve plate and a gasket seal for mounting the cylinder cover and the duct spacing of the present invention, as illustrated in the Figures 8 and 8a.

Figure 10 shows an exploded perspective view of a valve plate, spacing conduit and cylinder cover construction of the present invention, as illustrated in the FIG.
Figure 7.

Figure 11 is a front view of a different construction of the second embodiment of the invention, in which the spacing conduit is supported by the cylinder cover, mounting said spacing conduit in an intermediate plate that must be mounted on the cylinder cover.

Figure 12 is a perspective view of the cylinder cover and intermediate plate mounted on the plate valves, in accordance with the embodiment of the present invention illustrated in figure 11; Y

Figure 13 is a perspective view tidy up of the valve plate construction, spacing duct, cylinder cover and gaskets of the present invention, as illustrated in Figures 11 and 12.

Detailed description of the embodiments illustrated

The internal thermal insulation system for a hermetic compressor of the present invention is designed to be applied to an alternative motion compressor driven by a linear or conventional motor of the type used in systems of refrigeration of refrigeration apparatus, said compressor being, for example, of the type illustrated in Figure 1 and comprising, inside an airtight housing 1, a set of motor-compressor that has a cylinder block 2, in which a compression cylinder 3 is housed that houses, in a end, a piston 4 for compression of a refrigerant fluid and that it has an opposite end closed by a cylinder cover 5 or cylinder head, which internally defines a discharge chamber 5a that maintains selective fluid communication with a camera compression 6 defined within compression cylinder 3, between an upper portion of the piston 4 and a valve plate 7 provided between the opposite side of the compression cylinder 3 and the cover of the cylinder 5, said valve plate 7 having a front face 7c, against which the cylinder cover 5 is mounted, and a face rear 7d, which is directed towards the cylinder block 2.

The fluid communication between the interior of the compression chamber 6 and the discharge chamber 5a of the cover of the cylinder 5 is defined by a discharge port 7a provided in the valve plate and closed by a discharge valve 8a respectively, usually supported by the valve plate 7.

The gas extracted by the compressor comes from a suction duct (not illustrated) of the system cooling to which the compressor is coupled, being sucked from Selectively by operation of piston 4, during its cycle suction, into the compression chamber 6 a through a suction hole 7b, due to the opening selective of a suction valve 8b mounted on the plate valves 7, said gas being subsequently compressed until its discharge to the discharge chamber 5a in the cylinder cover 5. It generates heat during compression of the refrigerant gas, as has been previously described.

Figure 2 is a schematic view of the compression cylinder and part of the discharge system used generally in reciprocating compressors, okay With the prior art. The gas is compressed inside the chamber compression 6 by the piston 4 until the valve opening 8a discharge, which allows high temperature gas discharge and the pressure through the discharge port 7a inside the chamber discharge 5a of the cylinder cover 5 (as indicated by the continuous arrows in said figure 2) and, therefore, to the part Remaining compressor discharge system. With the process of compression, part of the thermal energy of the gas inside the chamber of discharge 5a, generated by compression, returns to the block of cylinders 2, as shown by the dashed arrows in the figure 2, resulting in an increase in the temperature of the cylinder, even considering the use of a seal 9, which has usually thermal insulation properties, being located said sealing gasket 9 between the valve plate 7 and the block of cylinders 2.

The present solution provides an insulation thermal inside the housing 1, which allows to reduce the flow of heat of the hot gas from inside the discharge chamber 5a to the region of the cylinder block 2, which has an impact positive in reducing the temperature of the cylinder block and, as a consequence, a reduction in compression power and losses due to excessive gas heating.

The thermal insulation of the present invention is achieved by providing the hermetic compressor with a conduit of spacing 20 having an inlet end 21, open towards the discharge port 7a of the valve plate 7 and external to the suction hole 7b thereon, and an outlet end 22, open inside the discharge chamber 11, defining said spacing duct 20 a tight fluid communication between the inside of the compression cylinder 3 and the chamber of discharge 11 and keeping the cylinder cover 10 spaced apart in the valve plate 7 at a calculated value to reduce the heat transfer from the gas in the discharge chamber to the valve plate 7.

In a construction option of this invention, the spacing conduit 20 has its end of inlet 21 hermetically mounted on the front face 7c of the plate of valves 7 and open towards the discharge port 7a, and its outlet end 22, for example, is aligned with the end of inlet 21 and is tightly mounted on the cylinder cover 10 and open into the discharge chamber 11, having the inlet end 21 of the spacing conduit 20 an area of the cross section at least equal to that of the discharge hole 7a, said spacing conduit 20 defining the communication of fluid between the inside of the compression cylinder 3 and the chamber of discharge 11, through discharge hole 7a.

In accordance with the present invention, the discharge port 7a of the valve plate is contained within the outline of the cross section of the inlet end 21 of the spacing conduit 20, circumscribing said section transverse more particularly the contour of the valve download 8a. In an embodiment not illustrated, the contour of the inlet end 21 of the spacing conduit 20 can be of any type, coincident or not with one of the end of outlet 22 or spacing conduit 20, that is, being more low or laterally offset relative to that of the valve discharge 8a, as long as it does not interfere with the flow of gas through of discharge port 7a.

The illustrated embodiments for the spacing duct 20 present the latter with a constant cross section along its length, including the input end 21 and the output end 22 thereof. Do not However, it should be understood that within the concept presented here, the spacing conduit 20 can have a section constant transverse between the input and output ends 21, 22 thereof, whose cross section may or may not be different from that of said input end 21 and output end 22. Said input end 21 and said output end 22 may have, by example, the same cross section, although this is not required.

According to an embodiment of the present invention, as illustrated in figures 3 to 5, the plate of valves 7 carries, for example incorporating it in one piece, the inlet end 21 of the spacing conduit 20, being obtained said incorporation during the formation of the plate valves 7 or later with the help of a fixing means suitable, such as, for example, welding, gluing, etc.

In this construction, the cylinder cover 10 takes, incorporating it in one piece, as illustrated in the Figure 6, or securing it by conventional means, as has been mentioned above, a front wall 12 to close said cylinder cover 10 and which sits against the outlet end 22 of the spacing conduit 20, with the interposition of at least a seal 9 in the middle, which is manufactured, for example,  of a thermal insulation material, in order to reduce the minimum conduction transfer of part of the heat flow to through the spacing conduit 20.

According to the illustration in Figure 4, between the valve plate 7 and the cylinder cover 10 are also provided with tubular fixing spacers 30, each of which is aligned with a defined fixing hole 7e on the valve plate and with a fixing hole 14 corresponding planned on the cylinder block 2, particularly on the cylinder cover 10, to allow passage  to a fixing element, such as a screw (not illustrated), which secure the cylinder cover 10 to the cylinder block 2.

In another embodiment of the invention, as illustrated in figures 7 to 13, the cylinder cover 10 carries, for example, incorporated there in one piece during its formation or fixation through suitable means, such as welding, gluing, etc., the outlet end 22 of the conduit spacing 20. In this construction option, the conduit of spacing 20 carries, in the region of its exit end 22, a peripheral flange 23 fixed against the cylinder cover 10 and which defines a portion of the latter wall.

According to the illustrations, the conduit of spacing 20 is provided orthogonally to a plane that contains the front face 7c of the valve plate 7, which is also orthogonally to the wall portion of the cylinder cover 10 defined by the peripheral tab 23.

In a constructive embodiment illustrated in Figures 7 to 10, the peripheral flange 23 is incorporated in one piece to the spacing conduit 20 during its formation, defining part of the assembly of the front face 12 of the cylinder cover.
book 10.

In a different embodiment of this construction, illustrated in figures s7, 8 and 10, the tab peripheral 23 of the spacing conduit 20 defines the entire face front 12 of the cylinder cover 10, being secured against it last and also against the valve plate 7, placing in the middle a respective seal 9. However, in cases where those that the cylinder cover 10 incorporates, in one piece, the peripheral flange 23 of the spacing conduit 20, the gasket sealing 9 is provided only between said conduit spacing 20 and valve plate 7.

In this embodiment it is provided also the provision of an outer cover 10a, as illustrated in the Figure 10, located around the cylinder cover 10 and allowing fixing the latter to the valve plate 7.

In another construction for the second embodiment of the present invention, illustrated in Figures 11 to 13, the peripheral flange 23 is defined by an intermediate plate 40 secured to the outlet end 22 of the spacing conduit 20 by suitable means, such as welding, etc. defining the entire front face 12 of the cylinder cover 10. In this different construction, the intermediate plate 40 can be previously fixed directly in the spacing conduit 20, without placing a sealing gasket 9 in the middle, and the latter it can be fixed to the cylinder cover 10, directly or with the use of a sealing gasket 9 in the middle, or it can also be previously fixed to the cylinder cover 10, before receiving the spacing duct.
to 20

In a constructive option, the intermediate plate 40 carries or incorporates tubular spacers in one piece fixing 30, as illustrated in Figure 11, providing, after mounting and securing the cylinder cover 10 in the valve plate 7, a space between the latter and the plate intermediate 40.

In this set, the spacing conduit 20 fixed to the intermediate plate 40 surrounds the region of the valve discharge 8a, creating a hermetic tubular region, which guides the gas which proceeds from the discharge hole 7a to the region inside the cylinder cover 10, defining there the chamber of discharge 11. Therefore, the discharge gas is retained in the volume provided by the cylinder cover 10 and the plate intermediate 40, preventing the passage of heat flow of this gas up to cylinder block 2, exactly due to the presence of the space between intermediate plate 40 and valve plate 7.

With the solution of the present invention, the reduction of direct heat transfer from the chamber of discharge 11 of the cylinder cover 10 to the already hot region of the cylinder block 2 allows to reduce the temperatures in this region inside the compressor, increasing the efficiency of Compressor compression operation power.

Although they have only been described and illustrated here some embodiments of the invention, should it is understood that modifications in the form and arrangement of the elements that comprise the compressor, without depart from the inventive concept defined in the claims They accompany each other.

Claims (17)

1. A hermetic compressor with internal thermal insulation comprising: a housing (1) internally bearing a cylinder block (2), in which a compression cylinder (3) is defined, which has an end closed by a plate of valves (7) provided with a discharge port (7a) and a suction port (7b), said valve plate (7) having a front face (7c) against which a cylinder cover (5, 10) is mounted defining a discharge chamber (5a, 11), characterized in that said compressor further comprises a spacing duct (20) having an inlet end (21) hermetically mounted on the front face (7c) of the valve plate (7) and open towards the discharge port (7a) of the valve plate (7), outside its suction port (7b), and an outlet end (33) hermetically mounted on the cylinder cover ( 10) and open towards the inside of the discharge chamber (11), presenting the inlet end gives (21) of the spacing conduit (20) an area of the cross section at least equal to that of the discharge orifice (7a), said spacing conduit (20) defining a hermetic fluid communication between the interior of the compression cylinder (3) and the discharge chamber (11) through the discharge orifice (7a), said spacing conduit (20) keeping the cylinder cover (10) spaced from the valve plate (7) and defining, with this lastly, an annular chamber around said spacing duct (20), preventing the passage of heat flow from the hot gas inside the discharge chamber (11) to the valve plate. 2. Compressor according to claim 1, characterized in that the discharge orifice (7a) is contained within the lathe of the cross section of the inlet end (21) of the spacing conduit (20). 3. Compressor according to claim 2, wherein the valve plate (7) carries on the outside on the front face (7c) thereof a discharge valve (8a), characterized in that the cross-section of the end of inlet (21) of the spacing conduit (20) circumscribes the de-valve
load (8a). 4. Compressor according to claim 1, characterized in that the inlet end (21) and the outlet end (22) of the spacing conduit (20) have the same cross section. 5. Compressor according to claim 4, characterized in that the spacing conduit (20) has a constant cross-section between the input and the output between (21, 22) thereof. 6. Compressor according to claim 5, characterized in that the spacing conduit (20) has a constant cross-section along its length. 7. Compressor according to claim 6, characterized in that the inlet and outlet ends (21, 22) of the spacing conduit (20) are axially aligned with each other. Compressor according to claim 1, characterized in that the inlet end (21) and the outlet end (22) of the spacing conduit (20) are hermetically fixed to the front face (7c) of the valve plate ( 7) and to the cylinder cover (10), respectively. 9. Compressor according to claim 8, characterized in that the valve plate (7) incorporates in one piece the inlet end (21) of the spacing conduit (20). 10. Compressor according to claim 8, characterized in that the spacing conduit (20) carries, in the region of its outlet end, a peripheral flange (23) fixed against the cylinder cover (10) and defining a portion of wall of the latter. 11. Compressor according to claim 10, characterized in that the peripheral flange (23) is incorporated in a single piece in the spacing conduit (20). 12. Compressor according to claim 11, characterized in that the peripheral flange (23) comprises an intermediate plate (40). 13. Compressor according to claim 10, characterized in that the peripheral flange (23) is fixed to the cylinder cover (10) in order to define an individual part with the latter. 14. Compressor according to claim 10, characterized in that the spacing conduit (20) is provided orthogonally to the plane of the valve plate (7). 15. Compressor according to claim 14, characterized in that the spacing conduit (20) is provided orthogonally to the wall portion defined by the peripheral flange (23). 16. Compressor according to claim 1, characterized in that it comprises tubular fixing spacers (30) supported by one of the valve plates (7) or the cylinder cover (10), each of said tubular fixing spacers being located (30) in alignment with a fixing hole (7e) defined on the valve plate (7) and aligned with a corresponding fixing hole (14) defined on the cylinder cover (10). 17. Compressor according to claim 1, characterized in that the spacing conduit (20) is fixed to at least one of the parts of the cylinder cover (10) and the valve plate (7), with at least one gasket sealing (9) made of thermal insulation material that is placed in the middle.